As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.
If this question can be reworded to fit the rules in the help center, please edit the question.

3

What would lead you to believe that there is an answer to this question that would be useful in any way? It is highly subjective, and almost certainly too localized.
–
ZoredacheJun 7 '12 at 0:16

Should have been edited to title, "Suggestions for obtaining a free realtime Linux distribution".
–
ewwhiteJun 7 '12 at 1:03

@JohnPristine What is the application for the realtime OS in your case?
–
ewwhiteJun 7 '12 at 2:43

The caveat is that simply installing a realtime distro won't automagically make everything faster. These kernels and related tools give you more "knobs" to tweak and ways to measure performance. This can be done for free (I've done it), but you will have to invest the time into working with your application and environment. Using the option I outlined, you can at least start with the RHEL MRG Tuning Guide.

On the tuning side, there's a lot more to work with in this realm. E.g.

Familiarize yourself with Ethtool and its options.

Investigate how interrupts work. E.g. what really happens when a NIC generates an interrupt. What does setting /proc/irq/irq_number/smp_affinity really do?

Do you actually have any data or anything to support your suggestion that CentOS/Scientific/Redhat Linux is the fastest? Or are you just suggesting it because you are familiar with it?
–
ZoredacheJun 7 '12 at 0:17

1

The OP asked for a free realtime distribution. There are other solutions that can be tweaked and tuned, but they're expensive. I suggested a free path that can provide high performance (with the right tuning steps for the environment).
–
ewwhiteJun 7 '12 at 0:25

That's awesome information! Thank you! I am not an IT guy so not sure I would be able to configure all that. I do understand IRQ, affinity, non-blocking, priorities, core isolation, etc. I wonder if I can buy this service from someone, in other words, if i can pay someone to install and configure a realtime os.
–
JohnPristineJun 7 '12 at 2:42

Yep. There are people who can provide this service. See my profile.
–
ewwhiteJun 7 '12 at 2:52

@ewwhite How do I find your email in your profile?
–
JohnPristineJun 7 '12 at 14:25